Just ran across this - I thought it was interesting: Cheap Sex and the Decline of Marriage.
Well, without reading the whole article (and i appreciate you going to the effort of printing to pdf and will read it fully if you can), i think this is where we are agreeing to disagree. Easy sex has always been available. Even before the 60's/70's free love movement, before birth control, if a guy wanted it, it was there to have. It may not have been as 'in your face' or considered acceptable as it is now, but it was there. "Thelyphthora" discusses this and was written/published in 1780.but rather pointing out that easy sex has resulted in the decline of marriage.
Let me see today if I can print it to PDF.